Screen plate and method of making same



Sept. 8, 1931. s. B. STINE SCREEN PLATE AND METHOD OF MAKING SAME Filed April 10, 1929 INVENTOR Patented Sept. 8 1931 UNITED PATENT: OFFICE SCREEN PLATE AND METHOD OF MAKING SAME Application filed April 10,

My invention relates to screen plates such as are employed in connection with shale crushing mills, and to the method of making the same. although it may advantageously be employed in connection with the perforation of metal sheets for other purposes.

One object of my invention is to provide a method of slotting screen plates by the use of a cutting flame, whereby slots can be more 10 quickly formed and with greater regularity, thus reducing the time and cost ordinarily required for forming a screen plate, and also having slots of more uniform or even width.

Still another object of my invention is to simplify and improve generally the method of forming screen plates.

In order to more clearly explain my invention, I have prepared the accompanying drawings, wherein Figure 1 is a plan View of a screen plate at one stage of its formation; Fig. 2 is a View taken on the line II-II of Fig. 1, and Fig. 3 shows the plate of Fig. 1, but at a later stage of operations.

In the accompanying drawings, I have shown a screen plate of somewhat the form disclosed in my Patent No. 1,658,056, issued Feb. 7, 1928, but it will be obvious that the plate may be of various other forms. In

making the plate, I first drill or punch holes 4 at the points where it is desired to begin the cutting of slots by an oxygen flame or the like. I preferably then heat the plate in a furnace or the like and begin the cutting operation by the use of a flame. The preliminary heating of the plate facilitates the cutting of the first slot, since time is not consumed in heating the metal by the torch, and by having a punched or drilled hole to start with, the cutting of the slot be- 40 gins immediately upon the application of the flame, thus avoiding cratering of the metal at the starting'end of the slot. The plate need not be reheated between the time when one slot is cut and the time of cutting the succeeding slots, since the temperature of the metal will be maintained by reason of the heat generated in the cutting of the slots in rapid succession.

Another important feature of my invention resides in the fact that I first cut a series 1929. Serial No. 354,147.

of slots 5 and then cut intermediate slots 6, as shown more clearly in Fig. 3. This pro-- cedure is followed for the reason that the slots in the completed plate are usually quite close together and may be only inch from center to center, that is, the longitudinal center line of one slot will be only inch from the longitudinal center line of the adjacent slot.

In cutting on such close centers, the metal becomes excessively heated so that if the cutto ting of one slot 5 were followed immediately by the cutting of an adjacent slot 6, the metal between the slots would become so hot that it would become distorted through warping and through excessive cutting of the flame. By my method, the slots are of more uniform width and the heat generated through the cutting of one slot 5, for instance, will raise the temperature of the metal such that it will be at an approximately proper degree for the quick and effective cutting of the next slot 5.

I therefore provide a method of maintaining a plate at a proper temperature for slot cutting, and one wherein theslots may be more quickly and uniformly cut, as aboveexplained.

I claim as my invention The method of forming screen plates having slots whose longitudinal center lines are spaced apart distances not substantially in excess of one-fourth of an inch, which comprises heating a metal plate, forming a series of perforations in said plate along lines designating the starting points of laterally-spaced slots, the perforations being spaced apart a distance equal to the slot spacing desired, applying a cutting flame to each alternate perforation in succession and moving the cutting flame along the plate to form slots, and thereafter applying the flame to the intermediate perforations and forming the slots intermediate the first-named series of slots.

In testimony whereof I, the said SAMUEL BLAINE STINE, have hereunto set my hand.

SAMUEL BLAINE STINE. 

